1. Salivary protein genetic polymorphisms. The long term objective is to better understand the mutation mechanisms that produce such an abundant variety of polymorphic forms in the saliva. The specific aim is to biochemically characterize mutant forms of proline-rich and histatin proteins by cloning and sequencing the genomic DNA of specific alleles at PRP and His loci. It is possible that genetic variation of salivary proteins, by altering the oral microenvironment, may relate to different disease susceptibilities among individuals. 2. Cell culture of Macaque and human salivary gland epithelia. The long term objective is to determine the intra and extracellular factors that regulate the expression of salivary-type genes coding for proline-rich proteins (PRPs), histatins, statherin and cystatins. These studies would be greatly enhanced by the availability of transformed salivary gland epithelial cell lines. The specific aim is to determine the conditions for primary cell culture of Macaque and human salivary gland epithelial cells and to transform them in order to establish permanent cell lines that express salivary-type genes. Perhaps this may lead to a better understanding of salivary-type gene regulation, and the principles so- derived might be used to manipulate and favorably alter the oral microenvironment in ways conductive to oral health. 3. Application of molecular techniques to the study of taste transduction in the mouse. The long term objective is to better understand the molecular basis of taste transduction. We have two specific aims: a. To prove directly by transgenic mouse experiments the role of salivary and von Ebner's gland secreted PRPs in the perception of bitter taste. Such a role is strongly supported by previous genetic evidence. b. To establish a taste cell-specific cDNA library in the mouse as an important resource in identifying molecules that play a role in transducing taste. These studies may increase understanding of the relationships between the chemical senses and the oral environment.